Stefan's photography: Typical post-processing workflow

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The following outlines the way I process my photographs. Documentation about photography post-processing abounds—in particular GimpGuru.org's tutorials are very useful—so I am only giving an outline; if you want to know details just contact me and I would be more than happy to ellaborate.

I normally shoot RAW, and I revert to maximum-quality JPEG only when memory card space becomes an issue (or when using the SD700 which produces only JPEGs). The workflow I outline below is the one for RAW photographs; JPEG photographs are first converted to 24-bit PNG images and then follow the same workflow (except that the first item is skipped).

• I first use Dave Coffin's dcraw in 16-bit mode (-4), with the camera's white ballance (-w), with this EOS 10D linear profile (-p), and with highlight reconstruction (-H 2). The result goes into pnmtopng (part of netpbm) and this gets me the 48-bit master PNG.
  • True, at the end of the day I end up with a 24-bit image, but the 48-bit output of dcraw is much better that its 24-bit output and I also attempt to keep the processing at the 48-bit level for as long as possible (which is not much right now, but I expect that the Gimp will be able to handle 48-bit images in the near future).
• At the same time I use exiftool to extract the original EXIF which is stored along with the photograph.
• I then load the master PNG into my digital darkroom, The Gimp. I process the photograph doing as few of the following steps as possible.
  • Layer->Colors->Levels: I adjust the levels and midtones to improve dynamic range.
  • Layer->Colors->Curves: I set the typical three control points and adjust the curves to increase contrast and brightness; I play around with the three points until the image looks right.
  • I increase colour saturation as needed using Vivid Saturation included in the Photokit GIMP plugins (often an increase of 6 will do nicely).
    • Out of the box alternative is Layer->Colors->Hue-Saturation (increasing saturation by 15-20% is often appropriate).
  • I use the curves again and play around with different colors and the center control point to white balance the image.
    • The white point is corrected if necessary using the color-wb-balance.scm script.
    • The Adaptive Contrast Enhancement (Filters->Colors->Adaptive Contrast) is also useful now and then.
  • I apply as needed specific effects such as blur overlay, ND filter, and contrast mask.
  • I then apply a smart USM sharpening using the Smart Sharpen (Redux) plugin (good starting point parameters are USM amount 2, USM radius 1, USM threshold 0, edge detect amount 6, and edge blur 7).
    • Out of the box alternative is Filters->Enhance->Unsharp Mask.
• In the process the image is converted to 24-bit depth, which results in a 6 to 12 MB PNG. I find this as the best compromise between size, quality, and convenience, so this is the end result of the post-processing. Since few tools support EXIF retrieval fron PNG images the EXIF information is kept as plain text and integrated into the albums by a modified version of flPhoto.

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Film photography

I no longer do film photography, so this comment is pertinent only to old photographs and old negatives. For these I use an Epson Perfection 1660 Photo scanner driven by SANE. I started doing scans at 350 dpi but then I increased the resolution (so that you might see scans anywhere between 350 and 500 dpi). I then put the result through the same workflow as above (and as needed).

Unfortunately the medium I scanned some—mostly older—photographs from was in a very bad condition, so you may see specks of dust and other artifacts in there (in some cases these artifacts rendered the photographs impossible to post-process).